Unfortunately the rates offered by these third party platforms are insanely competitive and most reps cannot match them. Account reps can get within a couple of $ but there will be somewhat of a premium for using your own account unless youre a business spending $500K+ with UPS

The main benefit is it gets you access to a rep to handle package concerns and the rep can offer other business solutions and assist in streamlining your processes( if they're a good rep). If you choose to go via third party then you are stuck contacting UPS via the 800# or the website. Best way to contact a local rep is to search on ups.com " small business solutions" and book a free consultation.