nthing the House D favour as essential to the build, although crafting looks like a useful angle and the flame arrow spell can conjure bolts as well as arrows. Doing the Shroud (for example) can easily use 300-400 silver bolts and 200 sturdy bolts (or 800 normal ones).
The real benefit of the house D vendor is access to metallic bolts - you won't find a silver / cold iron / whatever repeater except the alchemical ones, so if you want to break DR you either need a metalline weapon (which looses a prefix that could have been used for damage) or the House D bolts.
The Quiver of Alacrity from the Abbot is lovely - 3 x 1500 slots makes things easier, and you can get 4 x 1500 shot quivers from the DDO store.