B

Reverse Mortgage vs. Sale Decision Calculator

3.90

Derivation Chain

Step 1 Real Estate & inheritance decision simulation
→
Step 2 Post-retirement decision needed on how to monetize home equity
→
Step 3 Compare 20-year cash flows across reverse mortgage vs. sell-and-Jeonse vs. downsizing scenarios

Problem

Retirees aged 60-68 who own a home (market value 500M-1.5B KRW / ~$375K-$1.1M) need to fund retirement living expenses from their property, but cannot compare whether a reverse mortgage (Jootaek Yeonkeum), selling and renting via Jeonse (Lease Deposit), or selling and downsizing to a smaller apartment is the better choice. The Korea Housing Finance Corporation's reverse mortgage calculator only shows monthly payout amounts and cannot provide a comprehensive 20-year cash flow comparison factoring in capital gains tax, acquisition tax, moving costs, and investment returns on a Jeonse deposit. A wrong decision can cost tens of millions of KRW in opportunity cost over 20-30 years of retirement.

Solution

Users enter their current home value, location, age, spouse's age, and required monthly living expenses on the web. The service generates year-by-year 20-year cash flow projections for 3 scenarios (reverse mortgage / sell-and-Jeonse / downsize), each factoring in capital gains tax, acquisition tax, moving expenses, brokerage fees, Jeonse deposit investment returns, and national health insurance premium changes. Differentiator: compares 'net assets remaining at age 80' across scenarios to provide a clear decision-making framework.

Target: Ages 60-68, homeowner (property value 500M+ KRW / ~$375K+), pension income alone insufficient for living expenses, actively considering how to leverage home equity
Revenue Model: Basic 3-scenario comparison: Free. Detailed report (20-year cash flow + tax breakdown + net asset trajectory PDF) per use: 9,900 KRW (~$7.50). Auto-recalculation alerts on property value changes: annual subscription 19,900 KRW/year (~$15).
Ecosystem Role: Consumer
MVP Estimate: 1_month

NUMR-V Scores

N Novelty
3.0/5
U Urgency
4.0/5
M Market
4.0/5
R Realizability
5.0/5
V Validation
3.0/5
NUMR-V Scoring System
N Novelty1-5How uncommon the service is in market context.
U Urgency1-5How urgently users need this problem solved now.
M Market1-5Market size and growth potential from proxy indicators.
R Realizability1-5Buildability for a small team with realistic constraints.
V Validation1-5Validation signal quality from competition and demand data.
Each dimension is scored 1-5 and weighted into grade S/A/B/C/D.
SaaS N=.15 U=.20 M=.15 R=.30 V=.20 Senior N=.25 U=.25 M=.05 R=.30 V=.15

Feasibility (58%)

Tech Complexity
24.7/40
Data Availability
20.8/25
MVP Timeline
12.0/20
API Bonus
0.0/15
Feasibility Breakdown
Tech Complexity/ 40Difficulty of core implementation stack.
Data Availability/ 25Practical availability and cost of required data.
MVP Timeline/ 20Expected time to ship a usable MVP.
API Bonus/ 15Bonus for viable public API leverage.
Total 100 points; below 50% is filtered out.

Market Validation (58/100)

Competition
8.0/20
Market Demand
6.2/20
Timing
16.0/20
Revenue Signals
10.5/15
Pick-Axe Fit
10.5/15
Solo Buildability
7.0/10
Validation Breakdown
Competition/ 20Signal quality from competitor landscape.
Market Demand/ 20Demand proxies from search and mention patterns.
Timing/ 20Fit with current shifts in tech, behavior, and regulation.
Revenue Signals/ 15Reference evidence for monetization viability.
Pick-Axe Fit/ 15How well the concept serves participants in a trend.
Solo Buildability/ 10Practicality for lean-team implementation.
Total 100 points; below 50 is filtered out.

Technical Requirements

Frontend [medium] Backend [high] Data Pipeline [low]
Dashboard