If you're planning to have someone dig the pond, lay the liner, and add a few tons of rocks, then the price you were quoted is probably an average cost. There are ways you can do it for less.

When I put my pond in, the liner and equipment (skimmer, waterfall bio box, plumbing hoses, pvc glue, waterfall foam, and other assorted equipment, cost a grand total of $1,200.00. The catch? I dug the pond myself, got some friends and relataives to help me lay the liner in the hole, and did the plumbing work myself. It isn't hard. The rocks cost extra, but I ended up taking the rocks out anyway -- it looked great, but too much maintenance for my taste.

I personally wouldn't use the aquascape system. I'm sure their equipment is probably good, but they dump a ton of rocks in there and their calculations are often way off the mark, leaving you with less water volume than promised. I also don't like the stair-step shelf rings that invite predators.

If you want a liner pond and don't want to wield the shovel yourself, look into renting a mini excavator. They're fairly easy to operate, and you should have the job done in one day. The cost should not be much, compared to the price you were quoted for installing the pond.

Or, if you know some teenage boys who would like to earn a few hundred bucks for some hard labor, ask them to dig it for you. I have a friend who hired her garden men to dig her pond, and they had it done in one afternoon.

Some people are perfectly happy with their little preforms and stock tanks, though, so it's all in what you're looking for. For me, I like large koi, which cannot be placed in a small preform.

Go with the liner. ...and do it as big as you want it the first time.
Your biggest expense is going to be the liner.
Also, go with bottom drains. Makes things a lot more easy on you and safer for the fish not to have a pump inside the pond.

We put in a 15'x 32'x 3.5' pond and the cost was under $2000. (sorry I can't remember the exact amount right off) The liner was around $500. + shipping = approx. $600. BUT we did the work ourselves.
There's LOTS of info on the web. Lots of great koi pond websites and forums.

You can save money by hand digging the hole with shovels but if you can afford to have someone come in and use a backhoe I would.
Research first, then install the pond. Know exactly what you are getting into before you start.

I also agree with Nancy. I would not go with an Aquascapes system. Too many rocks. Then someone, either you or someone you hire(extra yearly expense), has to come in and clean the bottom of the pond every year. Just like a big ol fish tank that all of the crud settles in the rocks.

BTW, $10k is terrible for such a small pond; but then you are paying for labor when you have someone install it.

Ask all the questions you want. We can talk you through it.
~Karen

By all means, go with a liner pond. A preform is suitable only as a small water garden with possibly a few goldfish. It should never be used to house koi since they get so large and need a lot of space and filtration. And since you are in the planning stages, you have a wonderful chance to do it right. Bottom drains are such a wonderful thing. My big pond is 9000 gallons and 4' deep and I NEVER have to clean the bottom of it. It stays perfectly clean all the time, because the bottom drain carries off all of the fish waste to the filters. If you are worried about the sides shifting and settling, then build the pond either with a solid concrete collar around it (like a footer) or even better....a concrete block wall. The liner is then installed over the blocks and the rocks sit on top, fully supported by the block wall. I have built all of my ponds this way and they look wonderful.