Lightroom is standalone. They're currently on version 5.5, which you could automatically upgrade to from the base 5. I suspect version 6 is likely due out in the next year, but for what you're looking for you may not need to upgrade immediately. That said, the $135 you're paying for Lightroom will get you Lightroom and Photoshop for a year. You may not want or need Photoshop initially, but say 10 months down the road you want to try HDR, or focus stacking, or merging multiple exposures - you cannot do that in LR 5. You won't have to pay a dime extra to do it in Photoshop. And, if there's an upgrade, that's free.
The only drawback on the subscription service is that if you stop paying you lose access to the software in short order. So, if you decide down the road that photography is just an occasional thing, and you're only working on it once in a while, then having the software on your computer is a nice to have. For me, any way I've done the math, for anyone who will be taking pictures for the next two years and more, if you have $0 invested in software right now then it makes no sense to buy Photoshop or Lightroom now. I own both LR5 and CS6 and am on the subscription service because of what has been added to Photoshop CC and CC 2104 that I cannot get as an upgrade to CS6.
The price you found is the going rate for LR. If you have a student or teacher in the family, take advantage of the discount and get the Educational edition for about $75 - it's the version I have. You can always go on the CC subscription service any time you need to. Otherwise, jump on the subscription and buy the latest version of LR if you want and need to when you decide to cancel as it's supposedly going to exist as a standalone for the foreseeable future.