The basic kit of parts (PCBs, through hole components, etc) is EUR 180. Payment in Euro only.
You will then need to add a GPS antenna, 5 V DC (Mini USB or PoE to 5V splitter) power supply and cabeling for antenna head amps, ethernet, etc. The GPS antenna I got via Amazon and a seller in Hong Kong for GBP 2.20 delivered (took about 2 weeks), works fine, now GBP 2.68 <https://www.amazon.co.uk/gp/product/B008QV2ESG>. You may have USB power supply but note the plug needs to be a mini USB not a micro USB as used by most phone chargers. I went for a PoE solution, GBP 9.99 (Maplin UK) for a TP-Link TL-POE10R splitter, required a PSU filter, so a couple of chokes added about GBP 3.00, already had PoE injector.
Your choice of H field antenna (loop or ferrite) and what you have lying about to construct them with governs their cost. My H-field loops cost me nothing as I had suitable wire, timber, hooks and the bits to make the rotatable bearings "lying about". I had to buy a cable gland and a couple of waste water stop ends to house the E-field, maybe GBP 10.00.
Depending on your location you may need the optional filter ICs but until you have a working receiver your won't really know.
My location means I've had to install the filter chips, IIRC I managed to get four for less than GBP 50.00 delivered.
Finally theres is a nice custom case. However that doesn't have space for PoE splitter, power supply filter etc a "Really Useful" box does, had to buy that, another GBP 10.00 ish.
So my station cost EUR 180 plus EUR 12 delivery plus 2% paypal = EUR 195.84 (approx GBP 168.00) plus around GBP 85.00 as above = GBP 253.00 including the GBP 50.00 of filter chips.