After porting the BTLE library, I made something useful out of it, an Eddystone™-URL Beacon. I modified the BTLE library I ported to make it easier. There are 3 protocols defined, URL, UUID, and telemetry, however only the URL variant can be used due to the packet size constraint of the nrf24le1. A typical beacon is going for somewhere around $15.00 and the development kits for around $35.00. You can buy nrf24le1 modules on aliexpress for around $5 and a programmer for $3.
The main drawback to using a nrf24le1 is you only have 8 characters to work with for the URL. This is made a bit easier because the standard has abbreviated codes for http://www, .com, .net/ etc. I used 3.ly to make an address, qr.net/bfu3j, which fits into the space available. The other thing you lose out on is the over-the-air configuration, but that's not a deal-breaker.