Capsule
Capsule's free plan is the place to start. Users: Up to 2 users. Limits: 250 contacts, 1 sales pipeline. That's enough to run a real solo book before paying anything. The Starter plan raises the ceiling to 30,000 contacts, and there's no setup fee on either plan (Capsule lists it as None).
Close
Close's Solo plan runs $9 per user per month, about $108 a year. What you get: 1 user, 10,000 leads, no workflows.
Pipedrive
Pipedrive's entry Lite plan is quoted as $14 per seat per month, billed annually, so you pay for the year up front rather than month to month.
folk
folk's Standard plan: $24 per member per month, billed yearly ($30 monthly). Premium: $48 per member per month, billed yearly, and that's the tier to watch, because Email sequences start on Premium.
HubSpot
HubSpot's free CRM covers up to 2 users and 1,000 contacts, and HubSpot describes it as free with no expiration date. Signup needs no credit card required. Paid seats begin with Starter, which starts at $15 per seat per month. HubSpot's CRM page doesn't publish the billing term next to that Starter price, so check it before you count on month to month.
Every one of these plans is priced for one seat, so the real question is which limit you'll hit first: contacts, leads, or features.