I know that Thunder Tiger 4-strokes don't cure cancer or make you more attractive to the ladies like O.S. Max or Saito 4-strokes, but they are a great engine at a great price. If 4-stroke inflation is holding up your next big RC project, you might do well to consider them.

Thunder Tiger 4-strokes are the same great value as always at http://www.thundertiger4u.com :

$179.99 F-54s
$169.99 F-75s
$194.99 F-91s
$TBD F-130s

They even ship orders of $150 or more for free, so all of the four strokes qualify.

You can shop around at a number of Thunder Tiger dealers or order what you like from your local hobby store. Any lhs that sells Raptor helicopter parts can order a Thunder Tiger 4-stroke for you. Check out some other resellers:

http://www.infinitehobbies.com
http://www.ehobbies.com
http://www.paulsmodelsupply.com
http://www.radicalrc.com

I know my local Hobbytown USA will match thundertiger4u.com's $169.99 price on the F-75s. One of our club members ordered one in and that was simply the price Hobbytown quoted him on it. Another club member just maidened his Nitro Models Extra 330 .90 with a Thunder Tiger F-91s this week, and it looks, sounds, and flies great. I have a TT F-91s in my Ace Staudacher S-300 ARF that has been easy to break in and a terrific running engine.

I'm not suggesting you go out and do something crazy like try a Magnum 4-stroke or anything like that (although I own a .52 RFS and it's terrific also). I'm just saying that if $299.99 for a .56 4-stroke seems high to you, you might consider giving Thunder Tiger 4-strokes a try.