Is a decent small amplifier that can often be had on Ebay in the UK for less than £20. Sometimes they sell for over £100, but that's rare, and a scruffy one can sometimes be had for just a tenner. I own two (and parts of a third for spares), one in the living room and a second scruffy one in my workshop.
This amplifier was Britain's first transistor hi-fi amp in 1965. I'm not sure when the last ones were made, but as the 30 plus used silicon transistors rather than the Mullard germanium's found in the original Stereo 30 I'd guess they were only made for a few years.
They do sound better if the electrolytic capacitors are replaced. Maybe you can get away with just replacing some, but there's no need to use expensive ones, so it won't cost much, or take long, to replace them all (if you can solder).
The speaker plugs for these amps can change hands for more than the amplifiers! Madness! Although the genuine article looks unusual all that's needed is a 3mm (wander) plug and a 4mm (banana) plug for each speaker. Unfortunately new 3mm (1/8 in) wander plugs can be hard to come by these days - they were very common when these amps were new - they are still made by Belling Lee. Farnell sell them, though not cheap they're still cheaper than the genuine Leak plugs on Ebay, and just as good, perhaps better.
The slider switches on these amps can fail completely or become very noisy. My solution to this is to decide what setting you want for the inputs and tape output and solder wires to make that setting permanent.