actually, it shows how much of a liability they are to the retailer!
all this gear is not at the shop on consignment basis - meaning that the manufacturers just send the stuff over and take money only when the item is sold. the retailer (in this case blackwoods) buys the equipment at dealer price and sells at a mark-up over that dealer price. so essentially when they purchase the equipment at $abcd, they are taking on $abcd amount of liability, since there is always the possibility of that item not being sold and just becoming a white elephant. case in point is Lee's legendary collector's Playboy strat with the nekkid girly pic. When i started playing guitar 13 yrs ago, that strat had already been in display in the store window for a while. Even after they moved from plaza sing to taka, then to bras basah, the strat went with them. it was great for the cheekopeks who liked to gawk at the nekkid girly pic on the guitar but they just couldn't move the darn thing! and that thing cost at least 5 figures. Dunno what happened to that guitar in the end, think that they sold it for way below valuation.
so if a retailer doesn't bring in a particular brand, or asks customers to pay upfront for a piece of gear, chances are that they think the item won't sell in Singapore and so its not worth it for them to bring in the item on their account.
fyi

Diezels, as godly and powerful they are, arent the most popular of amps here, due to price and people's tendency to move to more popular brands.
In the US, Diezels are hugely popular; come on, seriously, they are really great amps. More people should play them.