herrera,
The amount of increase you get is dependent on your person credit file. If you have a thin file or several other credit problems you will not see as big an increase. I saw a huge increase because rehabing my student loans removed the only baddies on my credit report. The loans were also 10+ years old. So by fixing my student loans I restored my payment history to 100% and removed all negitave remarks on my account. When the loans begin reporting on my credit again as paying as agreed it will increase my AAoA. I hope to see another 20-30 point bump.
You really have to look at all of your accounts and not focus just on the student loans. If you have other late payments or collection accounts working to get those removed will boost your score. I went from having 3 defulted loans to a 100% clean credit report. There will be a huge score jump for you if you have a similar file.
Hope that helps.
Find out how the original creditor is and who the collection agency was. Send out good will letters to both asking to have the account removed. You may have some luck. If the accound says paid and it has a $0 balance it will affect your score. How old it is and how much the original amount was as well as any remarks can be factors. If you're able to good will it off your report you should see an increase. Is it a credit card? retail accound? Loan? phone company?
My student loan rehabilitation with ConServe ended 12-29-2015 and I am still waiting to have my loans picked up by a new servicer... 
Update: My loans just started reporting to EQ. I got a bump from 1.4 years AAOA to 4.6 years and a 21 point bump in my score. Still waiting on TU and EX