No idea , I know it's a bit vague but what did a large saloon cost in those days ? Maybe that sort of price ?
Well, despite digging through all my motoring encyclopaediae, I still don't know what the car is, but from some of the construction details (for example the foot-high chassis siding, between skirting board and bodywork, and the "artillery" wheels), I reckon it's roughly contemporary with the 1923 radio.
So, example prices of decent sized cars, in 1923 (depending on bodywork):
Austin 20: £695 to £975 (that's now £36,405 – £51,071)
Austin 12: £450 to £600 (£23,571 – £31,429)
Standard 14 Saloon: £375 to £525 (£19,643 – £27,500)