To optimize your crawl budget for e-commerce sites, you can start by allowing the crawling of important pages in Robot.txt File. This will ensure that relevant pages and content are crawlable and not blocked from the robot.txt file. You can also avoid long redirect chains, manage URL parameters, improve site speed, update sitemap, fix HTTP errors and work on internal linking ¹².

Source: 
(1) What is Crawl Budget ? 7 Tips to Optimize Your Crawl Budget - Infidigit. https://www.infidigit.com/blog/crawl-budget/
(2) How to optimize your website’s crawl budget - Search Engine Land. https://searchengineland.com/how-to-optimize-your-websites-crawl-budget-328273
(3) Crawl Budget Management For Large Sites - Google Developers. https://developers.google.com/search/docs/crawling-indexing/large-site-managing-crawl-budget
(4) What Is Crawl Budget & How to Optimize for It - LinkGraph. https://www.linkgraph.com/blog/crawl-budget-optimization/
(5) SEO Crawl Budget Optimization for eCommerce Sites | Inflow. https://www.goinflow.com/blog/seo-crawl-budget/