I love Datex, it does make things easier to slip in and out of, but there is a trade off when it comes to the cling feeling that a latex piece of clothing offers
I mainly wear latex for the look of it and the reactions I get from other people when they see it. The feel of it and the sensations you feel through it would be the next reason.
I lovr that you can get a variety of patterns and styles, so I would consider the colour useful, even though the majorit of my pieces would be the classic black
For some reason I would expect to pay less for datex, but that just might be a name association thing...kind of like how diamondex would be worth less than diomonds
For a perfect fit catsuit with some nice designs and such, I would pay somewhere in the 200-300 range
For a Datex version I would expecting to pay less so somewhere in the 120-180 range
Most of my fetish clothing has been bought from a brick and mortar shop, I find it easier to check sizing and such. Some of the smalle pieces like underwear I have gotten from lovehoney though.
Hope this helps!