Pay for delete or wait it out?

Im in the process of repairing mine and my wifes credit. Both our scores are currently in the 590s. We have a mortgage and auto loan in both our names that is current and never late, and i have a student loan in my name that is current and never late. I recently opened a secured credit card in both our names.

I pulled our reports and noticed on mine i had 2 collection accounts from 2006. one from Sprint wireless for $40, another from the local community college for $300. The community college account i recognized as a tuition bill i never paid, but not the sprint account, as i am still a customer and find it hard to believe my account was in collections yet still active. After 3 days on the phone w/ sprint we were able to verify that back in 06 they did a system switch over and some glitch left an unpaid balance of $40 that ended up in collections. They told me there was nothing they could about it from their end since it was already sent to collections.

I called the collection company and offered to make a settlement payment in exchange for deleting the account from my credit, they said that was not possible, but still asked for a payment. I told them if they weren't going to help me then we had nothing to talk about and hung up.

My question is, am i better off attempting to haggle with the CA for a pay for delete? Or since the debt is is from 2006, should i just press on with my current situation and wait the last 2 years of the statute of limitations for it to fall off on its own? I'm almost afraid to attempt the $300 account if i cant the CA to budge on a $40 account.

Also, have you noticed if the pay for delete method works better negotiating on the phone or sending a letter?