Some ideas for the achievement shop:
Outfits (portraits): no matter how many are still going to be added, you most likely will pick only one at most, therefore not the best ap sink.
Additional hairstyles, the hidden beards, eyewear, special backgrounds, and even more ear types and antennas (by shapeshifting) could further expand the selection to spend more points here.
Music: definitely worth the points, no matter how many tracks are still going to get added.
Phone: similar like the outfits. You might pick one new background and ringtone but that's it.
Instead of providing mainly skill points to avoid grinding, the shop needs more unique fun stuff you don't want to play without:
- player room deco. Instead of a money sink, offer these exclusively from the a-shop to lure players to spend their aps here
- special companion gifts turning into even more special room deco
- companion outfits and accessories. We already have many clothes but still lack more jewelry, hair accessories, and eyewear like shades, basically small cosmetic objects that won't take too much work to create
Maybe more ideas will come with the additional locations and activities that will be added with the next versions.