It depends greatly on what you are using the laptop for.
If your needs are basically email, internet/forum browsing and light spreadsheet use then basically anything you buy will be up to the task. There are models all the time on Ebay/CL for < $100 that will work as an email browser.
If you need to do more processor intensive tasks like video editing, gaming, data wrangling (say, with >100,000 lines of data), or generally working with larger files the current 'entry-level' full-feature laptops (e.g. not chromebooks) will outpace the ThinkPad T450. But again, if you are just emailing and browsing, you're unlikely to notice or care.
So... what's your basic use, and what's the most intensive use you anticipate?