The huge volume of advertisements was common for most magazines in this genre. In the UK this led to an interesting pricing / tax issue.

Value Added Tax is a tax putatively on, as the name suggests the value you've added. For a consumer you don't care whether you paid £15 for this product because it was £10 plus 50% VAT, or it was £15 with zero VAT, that's the same to you, and so the law says the advertiser can't say that's a £10 product even if there is 50% VAT, 'cos consumers can't buy it for £10, so you're lying to them.

However, if you're selling products for businesses, they're going to claim back the VAT on inputs to their business, only the added value gets taxed and that's implemented by charging the tax on their sales and allowing them to claim back the tax they paid for inputs. As a result it is allowed in that context to display the explicitly without VAT prices, your buyers potentially won't pay that tax anyway. So for a business you can say it's a £10 product.

The question in these magazines was: Are the products for businesses, or, are you actually selling to the hobbyists who often buy the magazine. You obviously want to advertise the lower prices with just an asterisk leading to a disclaimer about VAT to be paid, but if in reality most customers are hobbyists they're all paying VAT so maybe you're breaking the law by advertising the lower price?

Actual adverts definitely varied in how plausible the two categories of buyer were. How many businesses need to buy this slightly nicer Joystick for the Commodore 64? On the other hand, what hobbyist needs to buy hundreds or thousands of 10MB hard disks or SIMMs (yes the DIMM's predecessor was named the SIMM) for a discounted volume price ?