I'm dealing with this exact same thing and it's so stressful!! Building on the earlier suggestion, check Sephora at Kohls. It's a fantastic, reliable way to find the previous price because their inventory updates slower than the main site. I love this trick for staying on budget! It's an amazing way to save!!

Saw this earlier but just now responding. Quick question tho, which specific serum size are we talking about? The 15ml and 30ml price trends usually behave differently. Honestly, most extensions are unreliable with Sephoras backend. In my experience, Ive found it safer to use:

• Google Shopping historical price insights
• Manual Wayback Machine checks These methods are way more reliable than buggy scrapers.

Sephora is actually pretty annoying to track because they change their site architecture often, which breaks most scrapers. I spend a lot of time looking at price data and standard tools like CamelCamelCamel definitely wont work there. You basically have two or three specialized options for this kind of data.

• Price Before: This is probably the closest thing to what youre looking for. It maintains a database specifically for beauty retailers. Pros: it shows historical charts and low/high points over several months. Cons: the data refreshes can be slow and it sometimes misses flash sales that only last a few hours.
• Wayback Machine: This is the manual way to do it. You paste the Sephora product URL into the Internet Archive and look at snapshots from a month ago. Pros: you see exactly what the page looked like, including any promo banners. Cons: it is tedious to navigate and they might not have a snapshot for the exact day you want.
• Karma: This is a browser extension formerly called Shoptagr. Pros: it watches the item for you and pings you when the price hits your target. Cons: it usually wont show you history from the past... it only starts tracking once you add the item to your list. Checking Price Before is your best bet for immediate data. Drunk Elephant prices are usually static unless there is a site-wide Sephora sale like the VIB events in April or November. If the price looks higher now, you probably missed a recent 20 percent off window. Honestly, if it is for a birthday next Friday, you might be stuck with the current MSRP unless you find a set or bundle that has better value per ounce.