In the marketplace you could:
-Browse random items
Ex 1) Click 'random item' button and it will come up with a different item everytime you click it.
Ex 2) Click the button, Walker-bro shows up, click again, Cyblade +0-+7 shows up.
-Look through non-specific items sorted by, Price Low to high, or, Price High to low
Ex 1) Click Low to high, first item that shows up: Elektra arm +2 - 1 gigas. Last item, Super-Doubler - 99,999,999 bot stract
-(Addition to the one above) You could sort it low to high, etc, but with coins, gigas, or bot stract.
-Try on Items. You could try on a jack head or other items not available in shop
Ex 1) Haloween set, Arma soldier, Dark meto, haloween transformation, Bots e.f.s, etc.
-Check the average price for an item
Ex 1) You are trying to sell a bout cheetah E.F. for 72m gigas on the market, and you don't know why it isn't selling.
Reason: Too high of a price
Solution: Go to the price check of the marketplace where you can check the average price that items sold for on the market.
I know it'd be hard to implement ( at least for me), but in my opinion it would be worth it.