Price search isn't something forum type marketplaces normally encompass. I do agree that price searching can make it easier for people only wanting to invest in $1 to $5 domains (As per a previous question by you).
Please note that we have a Bargain Bin Forum full of $20 or less domains for sale. That would be the optimal place to find the cheap domains for sale.
Also Note that if you ever wanted to invest in a domain at $1k+ we have a High Priced Forum. This forum helps keep the higher value names separate from the mediocre names just like the bargain bin helps keep the low quality names separate as well, making the locating of domains by price a little easier, yet not as optimal as a pure marketplace.
As a forum we aren't really set up to be like pure marketplaces with price search (E.g. sedo / godaddy / etc.). Eventually our parent company Bodis.com will be launching a Marketplace and it will be equipped with the price search feature you are looking for, I'll update you once that rolls out.
Keep in mind, at the end of the day, NamePros is still based on a forum framework.
Eric Lyon