MechaEmperor7000 wrote:This is probably one of the best times to start
40k as nothing is overtly powerful or overtly underpowered. There are some outliers, but don't let the forum hysteria fool you; any perceived weakness is marginal at best. Pick what appeals to you the most, as
40k has a known history for armies going up and down in strength with every update. There has never been a universal constant.
As for nids, I would recommend getting a Tyranid Swarm Box and a Start Collecting! Tyranids. This should give you enough models to make a decent army to start off with.
I'll second this completely.
Get what you like and more importantly, what you will still want to play when it sucks.
I've been playing Terminators in Land Raiders for quite a while now and have gone from "Terminators suck and Land Raiders are overpriced (and if they don'd blow up from a lascannon hit they immobilise themselves on shrubs)" to "Terminators are amazing and Land Raiders don't die".
I'm under no illusions though that those models will at some point go back to being awful so should you. If you prioritise your purchases on their power right now you'll be disappointed further down the line.