In may be the case that these specific fuses are actually price accurately... Your links can not determine this though since they are popular companies. To find the cheap "deals" you gotta shop around and look towards the smaller companies that need to be competative to stay in business. Just showing that a few objects exhibt property A doesn't mean that property is universal for all those objects.
Look at ebay for some potentially good deals... He'll have to search if he's going to try and find a deal because if it was easy then it wouldn't be a deal.
I gave examples that show how one can easily get ripped off... I am not implying that this is the case here but chances are it is(ofcourse it might actually be worth it if its more trouble to try and find the good deals... no use wasting time over saving a few cents). If he's only blowing a fuse once a year then its no big deal but if he's blowing them once a month then it might pay to shop around.
My original point was that one just needs to know that it usually pays to shop around... sometimes it doesn't pay much and its not worth it but one shouldn't assume that these businesses are out to give you the best deals.
I saw on ebay some ceramic fuses that were similar to the one he needed for about 100/10$. Lets suppose that these are have slightly lower rating... don't you think it might be a good idea to purchace a few? One could then use the lower rating in the meter for cases where they would work and use the high rated ones when they are actually needed(i.e., when you are actually using the meter to measure current near its capacity). I'm sure one wouldn't mind blowing a few 10c fuses every now and then... ofcourse it may be more of a hassle to put the fuses in though than its worth.
Lets suppose the fuse for the meter is rated at 20A's... but you rarely, if ever, use it near that... you tend to measure only a few amps, lets say <
10A. Now, you end up blowing a lot of fuses because of accidents. You can by 16A fuses for 10c while the 20A's cost 2$. Wouldn't it be a good idea to pick up the 16A fuses and use them... if you ever need to measure between 16 and 20A then you'll know when you blow the fuse... it was only 10c so no big deal... just pop in a 20A fuse for that instance then afterwards swap it with a 16A. If its easy to swap on the meter then this really shouldn't be an issue... if you have to take the case off and stuff then maybe its not worth it.