There are many factors to this question - every situation is different and unique. If they have a score above 680, no deragatories, no more than 3 inquiries in the last 6 months and a good credit age and history with an adequate amount of accounts then they will have potential good results.
The general estimation for figuring out the potential amount of funding a client can get is taking their 3 highest cards and averaging them. Once you have that number figured out you can multiply it by 3 for the low amount and 7 for the high amount.
Ex. 3 cards at $10,000 each all being the 3 highest cards = 3x$10,000 = $30,000/3 = $10,000. The low amount of funding could be $30,000 the high amount could $70,000. Keep in mind this is only an ESTIMATION.