At $1,000/month you're buying roughly 8–12 focused hours after agency overhead. Enough for ONE channel done properly (ads management for a modest budget, OR local SEO upkeep, OR a disciplined email program), plus a real monthly report. It is not enough for 'full-service marketing,' and any proposal claiming otherwise is spreading an hour of attention across six channels.
A fair $1,000 engagement names its deliverables: what ships every month, what gets reviewed, what number defines success. If the proposal lists services without quantities, ask 'what did last month's client at this price receive?'. The answer is the retainer.
The comparison worth making: $1,000/month is $12,000/year. Judge it annually against what the same money buys in tools-plus-your-own-time, and re-decide every renewal.