Hello Shadow,
$145 new for that pump is not bad.
You may find a similar pump on eBay for less, item 4642057981 for example.
Several manufactures make this type of pump.
I have a similar pump for back up to my 1/2hp 220vac pump.
Have not had to test it yet. Mine is 24v pump.
Best way to find the 12v pumps is look for RV pump. Or 12v pump water
If you try to buy a solar pump this become very expensive. Not sure why...
Just because it's for RV seems to make it more expensive, but less than solar.
Have fun,
Scott.