Let's face it. Search Engine Optimization (SEO) can be very expensive, depending of course on many factors. If you are on a low budget and 'strapped for cash,' you may want to consider selecting a page or few to optimize, instead of optimizing your entire website all at once. The following excerpt curated from Search Engine Journal tells us why.
From Search Engine Journal:
Search engine optimization can cost more than you might think, especially if you try to gain a higher rank in competitive niches (i.e. legal services, real estate, insurance, weight loss, etc.).
An efficient, cost-effective SEO strategy is all about your ability to prioritize. So, as a starting point, select only several pages to promote and optimize.
What pages are these? Well, it depends on your industry and specialization. If you are an e-commerce website, focus on your most competitive products. If you are a service company, select your first-rate offer or service. If you are a clinic, go with your most popular procedures. And so on and so forth.
An important factor to consider is the performance of these selected pages in search. For instance, if you want to optimize and promote two service pages but have the budget for only one, choose the page that already ranks better. Trying to cover all pages at once is useless. As a digital marketer, you are limited in time and resources, so keep your focus on the targeted pages. You can improve the rank of your key pages which, in turn, will give a substantial SERP boost to your site.