Discovery was about $10 million dollars an episode, it wasn't low budget.
The first season they pretty clearly blew a ton of money on the first two episodes, and then pulled way back on the budget for the rest of the season.
For example, look at how little on-location shooting there was. The show went to friggin Jordan for filming for a throwaway five-minute scene in the pilot, but after that? We had a scene from a Toronto library used in
Lethe, one nice away mission in
Si Vis Pacem, Para Bellum, and a brief foray to the gravel pit planet in
The Wolf Inside, and a brief shot from Vaughn City Hall in the Season 1 finale. This is very different from Seasons 2/3, where most of the episodes had location shooting (it began to decline once they used the Volume for the last two seasons).
Not only did Season 1 have little location shooting, but it was constructed in such a way as to allow for sets to be reused repeatedly. Episode 3 took place partially on a twin ship to Discovery. The MU arc allowed them to reuse the Shenzhou set. The Klingon Ship of the Dead sets were also heavily reused across the first half of the season. But mostly, the crew just stuck to Discovery - so much so that people began remarking early in Season 1 when they'd actually leave the ship (reportedly
Si Vis Pacem, Para Bellum was forced on the showrunners by CBS, because they understood Trek fans wanted away missions).
I could also put casting here as an example where the show seemed to cut back money over time. The show all but stopped introducing new guest stars after six episodes (when Admiral Cornwell was introduced) with the remainder of the show just involving the characters already established or their MU alters. The number of extras is also notably thinner the later in the season you go. For example, the spore drive chamber in Episode 3 is full of crew, while by the time they hit the MU, we're explicitly told Tilly is the only person working under Stamets.
Again, all of this is just an issue for Season 1. The budget ramps up in every way starting with Season 2. But it's hard for me to re-watch Season 1 and not see all the ways they clearly were trying to reduce costs to salvage the season budget.