I live in Australia and that's why I can't possibly get UDPP..... FYI,, i'm not into online shopping so yea...

is is possible for me to just use concealer as the replacement of eye primer??

yes you can.

I normally use transulent powder before I use eyeshadow so it stays put, conceler might slide off after an hour or two

yes but it's not as effective

of course!

http://www.youtube.com/watch?v=eBGIQ7ZuuiU

yes you can or if you use foundation just use that as a primer before you apply eyeshadow...you need to dot/dab carefully and working on with your fingers or itll look thick/fake. practice using a tiny bit and add more if you need to. fingers are always the best tools!