If you specifically told the landscape designer that your target budget for the installation was 6K then s/he has an obligation to provide you with a plan that reflects that budget. I suggest you have a meeting w/ the designer and emphasize this again and request that they redesign the plan with this target price in mind.
Please be mindful that there will be a 15-20 % price fluctuation from your requested budget due to different firms charge differently for their labor + overhead.

the possible difference in plant count could reflect the spreading size of different plants.
As an example one ceanothus horizonalis plant will cover an area 10 feet x 10 feet. As opposed to a single sedum succulent that may cover an area that is 10 inches x 10 inches.

When comparing installation costs look at the plans to make sure the specifications are being bid apples for apples. If there are no specs then I suggest that you either have the designer write them up or you do so that you have a legal document that spells out exactly how the job should be installed. This will eliminate wide price swings and keep everybody informed of what type of quality is expected. No specs = no responsibilities/obligation = no guaranty of outcome.
Everything from soil prep, compost amounts and depths + how it is to be worked in , rough and finish grading, planting notes inclusive of tree staking, plant depths, irrigation notes, mulch type and quantity and clean-up.

"Maybe his fee is just too high for the plan, but the other interesting piece is that his plan included 438 plants/flowers/shrubs and another company who provided a free plan only included 53 plants/flowers/shrubs for basically the same area!!! Why such the disconnect??? "

- what d-d said is a definite possibility. Another possibility is simple economics of time. Your paid designer had every reason to take the time to create a nuanced and layered plan because he was being compensated for his time. If I'm giving you a free plan, I'm crapping out the simplest thing I can get away with and still hope to close the deal.

"We also got a quote from a landscaper guy who would just charge 1,200/day to do the work if we supplied all of the plants that he said he could purchase w/ his wholesaler discount. He said it wouldn't take more than 2 days, but the other guys say 7-10 days....just cannot figure out why such the variance! "

- it's never the really good, knowledgeable installers who make offers like this, you know? I don't know where you are but here in DC metro $1200/day gets you 2, maybe three guys. Good luck doing the work you described in two days, especially planting 438 plants.

- if you're getting the plants at wholesale, the wholesale yard will not warranty them for you. If your guy is charging you labor only and having you pay for the plants, he's not warrantying them.

I'm curious about why you paid a landscape architect and yet you also solicited a free design for the same space and it sounds like you're working around or without him?

I agree with some of the points made by my 2 colleagues. I would add that there is not really a way to get to the bottom of your specific problem without seeing and studying the plan (which, of course, none of us would wish to do any more than a lawyer would like to review contracts for free ... for fun. And usually, these plans are almost impossible to read when submitted here.)

One factor could be that there exists, among some (many) members within the trade, the notion that more plants = a better, more likable design. And the pressure, in certain situations, to sell plants can be strong.

You might get another bid or two to see if any trends emerge. And you might consider asking those who have already submitted a bid if they can identify what might be making the plan so costly to install ... and if they have any recommendations as to how it might (without too much trouble) be made less expensive. (It is not a given that you would with to follow the recommendations. They would be for your consideration, to use if they are useful.)

I would only add that a budget of 5-6K that includes both the plants, materials and installation would only get you a very cursory, small area design in my neck of the woods. Landscaping projects, involving a skilled, experienced designer and a reputable, knowledgeable contractor, tend to be a lot more expensive than most folks expect.

In this business you do indeed get what you pay for. I would be very skeptical about any low ball bids without checking out the past work of the parties involved. And make sure when you are comparing bids that they are for a similar scope of work - you need to compare apples to apples :-))

You stated up front your budget. Period! I would not go with any landscaper who pushed for more. His would be the first bid I'd throw out.

We have had many quotes all over the map for similar projects. Anyone who pushes for more will lose the job. You clearly stated your budget. This designer is not one who listens and therefore has no ability to communicate.

Sometimes their pretentious egos rule their projects. They want something to "brag" about, but you want something nice within your budget.

Be careful. Find one who listens and communicates.

Suzi

"You stated up front your budget. Period! I would not go with any landscaper who pushed for more. His would be the first bid I'd throw out. "

Slow your roll, killer. It's also possible the client had a $15k scope of work/wish list and a $5k budget, and the LA's goal was to present a plan that shows everything they WANT and now it's up to them to either find the money or figure out what they can cut in the scope of work. We do it all the time. "This is what you told me you wanted. Are you increasing your budget or are we value engineering to get you to where you're comfortable?"

Marcinde points out the never-ending dilemma ... wants vs. willingness to pay for.