VZ Lumina with a noisy Belt

[gatty]

Have just had my Lumina checked for a rattling noise coming from the belt. The mechanic applied some dry lube to the belt, but now it seems to be slipping and making a chirping noise when accelerating but not the rattling noise. The chirping noise slowly disappears after about 10 minutes.
I will be selling the car soon and was wondering what the best alternatives would be to have this fixed at a minimum cost

[mattsv6]

Check the pulley I've highlighted below... its known to get dust and grit in the bearings and cause a squeaking noise.