Quantity   Component name
8 × Arduino Nano From eBay for £2.50 ish
1 × set of 50 WS2801 LED string lights eBay £27 ish
30 × simple, panel mounted pushbuttons £20 for 30
1 × load of cut MDF about £10 from local hardware store(B&Q), including cutting
1 × can of white primer £8 from B&Q
1 × can of white gloss £8 from B&Q
3 × power regulation boards (switch mode) about &#xA3;1 each from <a target="_blank" rel="noopener noreferrer" href="http://DX.com">DX.com</a> but other available on ebay, size is key for the repeaters
8 × power bricks (12V) &#xA3;2.23 each from ebay
8 × power sockets &#xA3;3.27 for a pack of 10 from ebay
1 × load of misc resistors from work/home stock
2 × 433MHz recievers (STX882 ASK) couple of quid from <a target="_blank" rel="noopener noreferrer" href="http://tindie.com">tindie.com</a>, make sure you get ones with a chip on, the others barely work.
6 × 433MHz transmitters (STX882 ASK) couple of quid from <a target="_blank" rel="noopener noreferrer" href="http://tindie.com">tindie.com</a>
2 × picture frames from ebay, couple of quid a piece
1 × 1 Meter of ws2812 led strip again off ebay, about &#xA3;20