Cheap flash?

I recently purchased some aputure trigmaster ii radio triggers (x1 transmitter and x2 receivers) from a forum member, and already have a metz 50 af-1. Been having a bit play and they work great.
Seen as though ive got an extra receiver, can anyone recommend a cheap manual flash for the other?
Theres some neewer ones on amazon for £29, but ive no experience of them. I dont want to spend too much, its just for a secondary off camera light source.

Maybe a Shanny? This would give you HSS (on camera at least) if you ever needed that.

Nigel, ideas?

I'm probably not the one to look to for advice on 'cheap' ! I've bought my flashes based on their versatility and durability, and didnt find what was needed in the cheap category.

I agree Richard that the new Shanny model offers great value,so no doubt is a good choice, as you say though, assuming a need for on - camera work as well.

If it's only for simple manual radio triggering then there's loads of cheap options online. But who's going to recommend any flash unit that costs under 50-60 pounds? I think you take your chances, you might be lucky and get one that lasts and is reliable, but you might not. Even a well known brand like Yongnuo have mixed user experience reports online. However it's fair to say that plenty of photographers on Pentax related forums do report good experience with Yongnuo products, so this is probably the most logical first place to look.

I'm assuming the triggers are manual triggers and not TTL. So you will not remotely be able to change power settings to the flash. This in mind, any flash gun of any brand will give you what you require. Look for one with manual zoom and manual power settings. Two off camera flash gives great versatility to portraits and the like. For under £30 the world is your oyster on ebay. Keep in mind the older flash guns were very powerful. But tended to have longer recycle times. If buying new the Yongnuo YN-560 ii is a good choice. You dont really need the iii or iv version as they just offer remote power changes. These have become a little more expensive sine becoming very popular. Though you may want to upgrade this option in the future. My personal recommendation if buying new..... The Godox TT600.
https://www.amazon.co.uk/d/Flashes/Wireless-Speedlite-Trigger-Fujifilm-Panasonic...