Have you looked at what 10gtek is selling? I tried two low-price SFP+ SR, multi-mode module vendors way back when I first got my CRS326-24G-2S+ switches and 10gtek's modules were the one that worked. Newegg is currently selling a four-pack of them for ~52 USD, and singles for ~18 USD.
The ones I have run warm (~50C in ~25C ambient) but I've had mine for something like four, maybe five years now and they're still working fine.