$7.49 is very good. IMHO, just renew them where they're already at.
Skip the discount club - that's not worthwhile unless one has hundreds of domains.
However, you may want to search around for GoDaddy coupon codes, though $7.49 renewal pricing will be hard to beat.
Be careful - if the $7.49 is already a special promotional rate (which it appears to be), coupon codes may not work as expected; double-check all amounts and watch for add-ons before checking out.
With all that said, you could likely get down towards $7 if you call them and are willing to renew all for 2 or more years...
If you have the funds, multiyear is probably the way to go, since domain prices keep going up - not talking just registry cost, but many registrars themselves are hurting and increasing prices on their own accord. GoDaddy is well positioned, but not immune from the economic realities; lower percentage of renewals; more difficulties in selling / renewing upsells.
Ron