I just had a similar experience with an old Anthony that became sick beyond repair. The advantage of having a Hayward is that everyone carries new ones and can serve old ones.
You can get a new Hayward SP 1 HP at a store for $350 and for $300 plus shipping on the Net.
I got mine at Seasonal brick and mortar pool supplies store for $350 with two years P&L warranty.

If I were you, I'd take the old pump to a dealer who offers both repairs and new ones at a reasonable price. They can open it up and assess what needs to be done at what price. If only one or two parts need to be replaced and everything else is in good shape and there's no corrosion I'd go for repair if it's no more than $100. Otherwise I'd go for a new one.
Make sure you tell the dealer that you're committed to get his service/sale no matter what way you choose.
Be cautious : Some dealers may quote you $500 for the same pump. Make sure you have a quote of $350 or less before you bring it for repair.