Roberts products are usually of a reasonable standard but I think that they're largely trading on their reputation from years ago. In my opinion, there are other firms these days which can produce radios of the same, or higher, quality at far cheaper prices.
Cambridge-based Majority is one such manufacturer. All of their products are made to a very high standard. Further, Velocity Electronics operates as their 'outlet store', meaning that you can buy (nominally) refurbished Majority products at substantially discounted prices. [I had to add 'nominally' there because the stuff I've bought from them always looks absolutely band new anyway].
I bought one of these for myself last year
https://www.ebay.co.uk/itm/Majority-Micro-DAB-FM-Hi-Fi-System-CD-Player-Internet-Wifi-Radio-Bluetooth/113732856000?epid=6042398132&hash=item1a7b01a8c0:g:wjAAAOSwsCdeT7Tu
It's an 'all singing, all dancing' device, that can receive internet radio stations from all over the world, together with DAB and FM services. It also plays CDs and can accept music streams from other devices via Bluetooth. It's got fantastic sound quality, with a decent power output, and can also be used as a clock radio I was so impressed with it that I bought another one as a 16th birthday present for my grandson, who also seems to be greatly impressed.
However if you're simply looking to replace your RD70 with another DAB/FM radio, then this is what I'd go for, from the same manufacturer's online outlet store. It's an absolute bargain, which is at least as good as the RD70 and not much more than a third of the price you've been quoted for a repair:
https://www.ebay.co.uk/itm/Majority-Girton-Stereo-DAB-DAB-FM-Digital-Portable-Radio-Alarm-Clock-Wooden/113622474587?hash=item1a746d5f5b:g:0X8AAOSw~y9ZEE4j