I have replaced all the incandescent light bulbs in my MH with LEDs that I bought on eBay. The main reason for replacing with LEDs is to reduce the current drain. LED lights will draw about 15% of the current for the same light intensity. They are also a lot cooler. If you want more light you can put larger (more LEDs) in the same fixture without risking melt down.
LEDs will probably cost you between $2 and $5 each depending on many factors.
When you buy, get 1 or 2 and try them. If you like them buy more. There is a big difference between sellers and you can't always believe the ads.
These are the ones I bought to replace my 1141 incandescent bulbs.