discontinued multiport

So after vacuuming the pool and having dirt blow back in, I took apart the multiport valve to have a look at the spider gasket. I think it looks ok-but not sure so I went to pool store to check out a new one. Was told that Sta-Rite discontinued the part and would need to buy a whole new multiport valve. Now I can't compare it to see if the part is good or not. The gasket is molded onto a larger plastic piece. At $150.00+ for the part I may just buy a whole new Hayward filter to hook up with my Hayward pump. The sand is 5 years old, could I reuse or buy new? Any chance the problem could be something other than than multiport? Thanks, Denise.