Christmas question

[Malhomme Olivier <malhomme@infobiogen.fr>]

For you all I would need a few informations and an advice.
I would like to buy a new reverb because the one I already have are too
bad (ie: ART SGE mach 2, Midiverb 4, DSP 1287). These reberbs have a too
much dinstiguable sound. I'd like a ransparent kind of space processor.
I'd like to hear the "size" of the place in thereverb, not the reverb
itself.
The bad thing is, I don't have much money. I could not go far from about
500 bucks.
Magazine tests led me to choose 3 competitors: Lexicon Alex, Lexicon
reflex, and Yamaha REV-500.
1) Can you tell me how much these are in the USA (an average STREET
PRICE) if one can...
2) Does any one sees reasons why I would choose one over the others (not
to mention some new model advice in that line of price. 
Thanx to everyone in advance.