Poppets and the Craft Poppet feat from Adventurer's Armory 2.
For a mere 2,810 gp, you get a tiny construct with a climb, fly, and swim speed. If it can reach it, it can leave a rope or grapple and then you can reach it.
The totally pimped out tiny version costs 5,710 gp, has AC 18, hp 15, walk and fly speed 30' with hover, climb and swim speed 20', a light load of 64 lbs, and a heavy load of 195 lbs.
The small version is just over double that at 11,500 gp, has AC 16, hp 25, the same speeds, a light load of 171 lbs, and a heavy load of 518 lbs.
Provided you can keep it from getting popped by a random fireball, that's enough to loot most dungeons with room to spare.
On the feat end, you can take Craft Poppet at 1st level. It is rather useless as it ONLY makes poppets. However, it counts as both Craft Wondrous Items and Craft Arms and Armor for the purposes of qualifying for Craft Construct, so you can save yourself a feat.