It's not too late to buy PRL to get SHL. The snapshot doesn't take place until tomorrow, 13 Apr 2018. There really is no way to tell what the SHL price will be. However, I would assume that it will initially list at the same price as SHL and then likely drop abruptly from there. However, the market is looking bullish so it may just surprise us all. I bought in when it was much higher in price for PRL so even now it is a great bargain.
I want to buy a PRL as well but still remember the NXT snapshot that got IGNIS. I lost about -50% because of this IGNIS airdrop. but i dont know what will be happened with PRL and SHL. i'll buy some PRL, i hope SHL will have a good price