Mini Monitors: Stands Vs Shelf Questions

#1 Do you think there a price cutoff point at which one should generally conclude, "These monitors are too fine/expensive to be compromised by putting in a shelf as opposed to dedicated stands?

#2 Regarding monitors with rear bass ports, are there any really good devices for wall mounting which will allow the speaker around 18"-30" out from the wall behind it and angle it to direct downward at the listener from an "unorthodox" height (say 48" to 80" tweeter height) and would this type of configuration provide sonic quality "close" to what one would expect using dedicated stands?

Thanks again.......Still weighing options for a computer room/office measuring 9.5' x 12' where the speakers must reside high up on the short wall.