Using one national supplier for costs:
A replacement Tagelus is about $780, plus sand(+~$130)
A Pentair CCP 420 that I love - about $1529
The XtremePower - $420 plus sand
The issue on the Amazon find is replacement parts. While not a lot can go wrong, you may need spider gaskets or o-rings for the multiport, at some time - generally if someone moves the handle while under pressure. Unlikely any other brands will fit. Equipment from the majors will generally have very long time availability for parts.
So there is a risk that the less expensive will be come more so, if you have to replace it due to lack of parts.
While I push my cartridge (the CCP 420 is great, and your pool looks very close to mine in size), and never needing backwashing is fantastic. - The double or more cost can be a big pill to swallow.
Here's more info with determining how big a filter you should have:
How to select pool equipment - Further Reading
If you add your pool and your equipment to your signature here, others with much greater knowledge can help with your size selection.
Create Your Signature - Further Reading