this tube is the industry standard in guitar amps typicaly costing £20uk or about $25us. it seems to me that the price is based on nothing more than what the sellers can get away with. this tub has a gain or u value of about 100 a good alterntive is ECC84 a pin for pin alternative with a u value of 80 cost of these is typicaly £8. for hifi these are a perfect alternative and for guitar amps they still provide the correct sound with all the crunch that is needed. very few amps are designed for absolute maximum gain so these are worth looking at if replacing preamp tubes