Prime has no start up fee.  You pay the annual fee and get the Prime Pricing.  You also receive exclusive coupons giving you a higher percentage off than regular coupons.

DAZ has a start up fee.  First year is $99.  Subsequent years if you do not allow your membership to lapse, is average of $69.  DAZ will put their PC membership on sale now and again but if you already have a PC membership, it isn't a matter of buying the cheap membership and it adds on as it used to before the new store software.  Now, if you don't auto renew by having a payment method on file (read credit card here as DAZ and PayPal are having issues), you have manually buy the Full Annual PC membership at $99 and they will refund the difference.  Oh, and if you had a payment method on file and removed it, DAZ has been known to charge your payment method when the renewal comes up even if they're not supposed to. 

Canecellation of the PC is now a major headache as well.

And to make things even more fun, with the departure of LisaB and her plants, PC members are finding out that not all of the PC catalog is owned by DAZ.  Seems that if a vendor becomes a DAZ Administrator, their products are really PA products and the vendor can pull them from the PC catalog if they leave.  So far this includes Jack Tomalin, LaurieS, and Moyra.  Seems it took them ten years and major loss to their PC catalog for them to admit that.

DAZ PC also gives you a $6 coupon each month that is only good on DAZ originals.  It is a use once, use it all or lose it coupon.  It does not extend into the next month.  It cannot be used on PC and Value items. 

If you look at new PC releases, they are all the PC price.  However, after 2 weeks, some of them end up in the Value Category at a higher price.  Which ones, they don't tell you that.

You do get a 30% discount all the time as a PC member and DAZ does give some perks to PC members but not as many as they used to.  Oh, and if you are in the PC you do get the weekly freebie for free without having to buy anything.

Prime is pretty straightforward.  Anything labelled Prime is in the Prime catalog at the Prime price.  Period.  Anything labelled Prime Classic I think is in there for 30 days.

One fee and one price.  July is the anniversary and usually when Rendo offers it a half off.  If you get Render Reward, you can use your Render Rewards GC to buy a Prime Membership.  Like DAZ, there is a dedicated forum for Prime members.  I believe you have more gallery space but I don't use galleries so it didn't matter to me.  DAZ hasn't been able to get the galleries up since the changed to the new site.

I may have skipped or missed something but that's the ups and downs of them.