To search for prices on e.g. Tamriel trade Center e.g. you'd need the name and other data which have to be put into an URL that thie website can interprete, so you need to check which website got what URL and get parameter to use for such kind of searches.
e.g.
Tamriel trade Center, Englisch language, EU server, "Bowl of worms" name of item ->
Code:
https://eu.tamrieltradecentre.com/pc/Trade/SearchResult?SearchType=Sell&ItemNamePattern=Bowl+of+Worms&ItemCategory1ID=&ItemTraitID=&ItemQualityID=&IsChampionPoint=false&LevelMin=&LevelMax=&MasterWritVoucherMin=&MasterWritVoucherMax=&AmountMin=&AmountMax=&PriceMin=&PriceMax=
You could add other serach parameters after each of the =, like level, quality etc. and just need to map the internal ESO values to the needed website Get parameter values in order to make it work.
BUT: I'm not sure what's the MAXIMUM lenght of the ESO website open URL popup! So keep in mind you cannot just put there a 10000 characters
long link e.g.