First - the reporting time limit is not 7 years + 180 days.
For credit cards it is 7 years from the first a person becomes 30 days late and never brought the account current leading to the charge off. For bank loans it is 7 years from the last payment before the default.
The 180 days is only "allowed" by the FTC to the CRA's for possible data furnisher error of the true obsolescence date.
The FTC requires the CRA's to report for 7 years from the true obsolescence date - not 7 years + 180 days from that date. <source - FCRA FTC Staff Opinion Letters>
To the OP, I've looked through the states collecting SOL list (the link listed in my profile) and I do not see a state that lists a 7 year SOL for either an open or a written account.
credit cards would be considered open accounts
bank loans would be considered written accounts
utilities - phone land and wireless, electric, etc. "generally" fall under the UCC with a 4 year SOL
repo's void the original contract and fall under the UCC with a 4 year SOL
As far as paying or not, and how much, really depends on what you feel you need to do.
If you "have" to have it gone within the next month, you do have to factor in that (after demanding removal upon payment) you will have to wait on them to delete.
One other thing, when you send anything to the collection agencies, never sign your name. Type your name in or print your initials. Send everything certified mail return receipt.
(going a little off topic for this question - just an FYI)
I noticed in one of your other questions that you said you needed your score to go up to a certain figure. If you know someone, spouse, family member or friend that has credit card(s) that are in good standing - no lates, low utilization, etc. Ask them to put you on as an authorized user.
If your spouse adds you, by law, the creditors and the CRA's HAVE to report the account(s). If a family member or friend adds you, the creditor doesn't "have" to report though many do. And while you are being added, request that they report. You can also ask how long it will take to start reporting.
It's a good idea to be added as an AU to more than one account, and with different creditors, in the chance one creditor doesn't report (if it is a family member or friend) or if a creditor is slow to start reporting
Being added as an AU, when the CRA starts reporting, you will get the FULL history of the account(s). And, if the account(s) is/are in good standing and have some age (brand new accounts won't help) - your scores should rise "past" the mark you had mentioned in the other question - even with your current baddies reporting.