Aye, the shop accepting gold is a very good thing for maintaining the stability of the TD economy.
For those interested in percentage changes, here are the changes from Version 25 to Version 27:
Commons
Bone Map Case - 25 to 5 (-80%)
50 foot rope - 20 to 10 (-50%)
Waterskin - 10 to 5 (-50%)
Steel Flask - 10 to 5 (-50%)
Flint and Steel - 15 to 10 (-33.33%)
Small Steel Mirror - 10 to 5 (-50%)
Grappling Hook - 25 to 10 (-60%)
Hammer and Spike - 25 to 10 (-60%)
Rares
Chain (+5 AC) - 40 to 35 (-12.50%)
Banded (+6 AC) - 30 to 25 (-16.67%)
Very Rares
Elixer of Life - 500 to 600 (+20%)
Ultra Rares
+2 Shortsword - 1000 to 1400 (+40%)
+2 Longsword - 1600 to 1900 (+18.75%)
+1 Full Plate (+9 AC) - 1500 to 1800 (+20%)
Ring of Evasion - 1200 to 1500 (+25%)
Cloak of Displacement - 2500 to 1500 (-40%)
Promos
Bag of Holding - 150 to 100 (-33.33%)
Mug of Wisdom - 200 to 100 (-50%)
Mug of Beauty - 200 to 100 (-50%)
Mug of Brawling - 300 to 125 (-58.33%)
Mug of Courage - 250 to 110 (-56%)
The obvious trend is towards a decrease in value of easily available gear and mid-range armor. The ability to readily acquire common gear from token bags, or simply find it lying around, decreases its value in trades. This gear may also be affected by a perceived lack of usefulness, which is similar to what has affected the promo-tokens. The ability of many classes to wear superior armor, which over the last couple years has become more widely accessible to the public, reduces the target market for mid-range armor significantly.
A collector's market combines with a drive by returning players to "be the best they can be" to drive the prices on upper level arms and armor upward. The most notable fall from grace also occured within the upper level ranks however, with the revelation that the Cloak of Displacement is not as unbalancingly superior as some folks previously thought it was. Despite its 40% fall however, it remains among the most valuable tokens in circulation.
Gem premiums remain constant from v25 to v27, powered in part by speculation that gems may have uses beyond cash in future True Dungeon events. A solid showing for common gear in the adventures at an upcoming convention may return strength to those tokens, but until such time, they are likely to remain a dicey investment. For the time being, it seems that Potions and Scrolls both remain solid options for those who wish to retain flexibility without losing value in their portfolio, while those looking for a high-stakes venture should look into the ever-changing field of magical weaponry.